Как правильно работать с балансом счета?

+----+---------+-------+
| id | user_id | value |
+----+---------+-------+
|  1 |       1 |   500 |
|  2 |       1 |  -200 |
|  3 |       1 |  -100 |
|  4 |       1 |    50 |
+----+---------+-------+

SELECT user_id, SUM(value) as value FROM balance GROUP BY user_id;